From a small frog to a giant elephant, most terrestrial, aquatic, and aerial animals are known to sleep. Sleep is an evolutionary process and a way for the body to regenerate, grow, and adapt. Early in history, the Greek philosopher, Aristotle, hypothesized that animals not only sleep, but also dream. Was he right?
From new research and tests, there is some fascinating evidence which hints that Aristotle may have been correct.
From scientists like Aristotle to researchers at MIT, we have been able to collect much evidence on this topic. When humans dream, they are in a state of sleep called REM (rapid eye movement). During this state, humans are paralyzed. In 1965, two French scientists found a way to remove a part of a cats brain called the pons. By removing this brainstem, the cat could move during the REM state. Instead of lying still, the cat moved around aggressively, suggesting it was dreaming. Similar activity was recorded on dogs.
With new technology, scientists are able to detect the electrical signals within the brain of humans and animals. Mathew Wilson of MIT’s Center for Learning and Memory conducted multiple tests in 2000 on rats to see if they dreamt about running through a maze they had recently completed. While the rats ran through a circular maze for a treat, their brain activity was being recorded, specifically in the hippocampus. After the rats had fallen asleep their brain activity was again recorded. The results were so similar and precise that Wilson could detect where the rats were in the maze and if they were sitting or standing for each reading – the awake and asleep.
Amish Dave and Daniel Margoliash from the University of Chicago recorded the activity of zebra finches brains as they were singing. The birds’ neurons in their forebrain could be decoded as individual notes that are put together to make a song. When the birds were sleeping, the neurons were being transferred as
notes in specific patterns, suggesting the birds were dreaming of singing.
Have these scientists proven if animals dream? Not exactly. Although this data can suggest that animals dream, there is no definite answer. If animals do dream, there is still so much more that can be learned about the animal brain. Do animals remember their dreams? Can they distinguish between the real world and their dreams? This extensive line of research leads scientists to understand more about the brain, which can help cure diseases such as Alzheimer’s.